GGU-RETAIN: "Dimension lines" menu item
You can include a vertical and/or horizontal dimension line in the graphic to illustrate the system dimensions. If the dimension lines are displayed on the screen, you can also open the following dialog box directly by double-clicking the left mouse button over a dimension line.

The distance to the wall or pile is defined by means of the "y position" for the horizontal dimension line and "x position" for the vertical dimension line. Negative values define a position above or to the left of the wall or pile. All values are in metres in the scale selected (see the menu item "Page size + margins/Manual resize (editor)").
The fastest way to modify the position of the dimension lines is to press the [F11] function key and then to pull the legend to the new position with the left mouse button pressed.